Digital Commons Network^™

Engineering Calpastatin To Develop A Sensor To Detect Active Calpain, Lisa M. Vanhooser

Electronic Theses and Dissertations

Calpains, Ca²⁺-activated cysteine proteases are essential for early embryonic development and function in signal transduction, cell adhesion, and apoptosis. Calpains also contribute to cataractogenesis, myocardial infarctions, and neurodegenerative diseases such as Alzheimer's. The various methods currently available to demonstrate these roles do not directly identify spatial or temporal activation of calpain in cells. Therefore, a tool to detect active calpain in situ will be useful. Calpastatin is the ubiquitous, endogenous inhibitor that specifically binds the active conformation of the conventional calpains. Calpastatin consists of four homologous domains each containing three subdomains A, B, and C. The crystal structure …

Determining Environmental Drivers Of Fish Community Structure Along The Coast Of Maine, Adrian Jordaan

Electronic Theses and Dissertations

The work presented here was conceived to determine whether structure in marine communities could be related to multiple scaled environmental parameters, as seen in lake and stream systems. Four datasets collected from 2001 to 2005 were used. The datasets ranged from local scale tidepool and estuarine surveys, to more regional intertidal/subtidal surveys and conclude using a coast-wide trawl survey. Initially, a bootstrap program for running principal component analysis (PCA) was developed and tested for utility with additional information from Pearson correlation coefficients. The bootstrap-PC A program was capable of determining confidence limits for correlations amongst species. The results from analysis …

Diel And Tidal Rhythms Of Emercenge Events Based On Acousitc Observations In A Shallow Estuary, Mei Sato

Electronic Theses and Dissertations

Field observations of emergence events by epibenthic animals were conducted with two Tracor Acoustic Profiling Systems (TAPS) in the Damariscotta River estuary, Maine, in fall 2005 and summer 2006. Spectral analysis revealed that periodic temporal variability of the acoustic signals was concentrated at four periods. One was the solar day (24 h) and the other three were lunar tidal periods of 25.82 (diurnal or Oi), 12.42 (semidiurnal or M2) and 6.21 h (half the semidiurnal period). The mysid Neomysis americana showed strong nocturnal migration patterns of water-column activity during its peak summer emergence season, regulated by the diel cycle. Toward …

Semi-Global Analysis Of The Early Cold Stress Response Transcriptome Of Developing Seedlings Of Rice (Oryzasativa L.,Japonica), Chen Cheng

Electronic Theses and Dissertations

Plants are either sensitive or insensitive to low temperatures. Cool-season species acclimate to chilling and develop tolerance to freezing. Warm-season species vary in the degree of sensitivity to chilling and are not capable of acclimation. Both freezing and chilling tolerance involve the activity of an intricately coordinated network of genes. The regulatory network that defines cold acclimation and freezing tolerance is well understood in Arabidopsis. The centerpiece of this network is a group of transcriptional activators that coordinate a battery of downstream defense-related genes. In contrast, little is known about the corresponding regulon in non-acclimating species. This study utilized …

Ecological Relationships Among Partial Harvesting, Vegetation, Snowshoe Hares, And Canada Lynx In Maine, Laura Robinson

Electronic Theses and Dissertations

Understanding the ecological factors affecting habitat use by the Canada lynx (Lynx canadensis) and its primary prey, the snowshoe hare (Lepus americanus), could help formulate conservation strategies for this carnivore, which is federally listed as threatened and occurs in only four regions of the U.S.A. I measured vegetation characteristics and snowshoe hare densities in 15 regenerating conifer clearcuts and 21 partially harvested stands in northern Maine during the leaf-off seasons, 2005 and 2006; and the leaf-on season, 2005. Regenerating clearcut stands had been harvested between 1974 and 1985 and were subsequently treated with an aerial application …

Modeling Large Whale Entanglement Injuries: An Experimental Analysis Of The Influence Of Tissue Compliance, Line Tension, And Draw-Length On Epidermal Abrasion Resistance, Jeremy Paul Winn

Electronic Theses and Dissertations

Two test systems were developed to evaluate the influence of draw-length and tissue compliance on entanglement-induced epidermal abrasion in humpback (Megaptera novaeangliae) and right whale (Eubalaena glacialis) tissue samples. Under straight pull abrasion tests an adult right whale fluke required 3.7 times the load and 15 times the draw-length of a right whale calf flipper to induce epidermal failure while a humpback fluke was intermediate between these extremes. Epidermal thickness did not appear to be the cause of this difference in abrasion resistance. Epidermal thickness averaged 8.0k0.2 mm for the calf flipper, 4.9k0.4 rnrn for the humpback fluke, and 5.1k0.1 …

Oxalate Production And Cation Translocation During Wood Biodegredation By Fungi, Jonathan S. Schilling

Electronic Theses and Dissertations

Wood biodegradation is primarily caused by Basidiomycetous white or brown rot fungi. White rot fungi are unique in degrading lignin, while brown rot fungi circumvent lignin to degrade holocellulose via iron-dependent oxidative chemistry. Both groups of fungi produce oxalate during wood metabolism, and oxalic acid secretion may promote wood decay by reducing pH, mobilizing iron, detoxifying copper, and immobilizing calcium. The function of oxalate during wood decay remains unclear, however, primarily due to difficulties in extracting bound oxalate and to inconsistencies among analytical techniques. This work aims to improve oxalate quantification during wood biodegradation and to better characterize fungal oxalate …

A Spatial Anaylsis Of Passenger Vehicle Attributes, Environmental Impact And Policy, Gregory M. Gould

Electronic Theses and Dissertations

Passenger vehicle use contributes significantly to energy consumption, criteria air pollution and greenhouse gas (GHG) emissions. Recent developments in Geographic Information Systems (GIS) and Vehicle Identification Number (VIN) decoding enable researchers to make use of vehicle registration records to consider the spatial distribution of the vehicle fleet when modeling emissions. In this thesis, these techniques are used to view spatial variation in passenger vehicle attributes and environmental characteristics. The distributions of vehicle type, make and model, size, age, criteria and GHG emission rates, and fuel economy are analyzed. Next, the spatial distribution of private costs and benefits resulting from a …

Physical And Behavioral Development Of Nursing Harbor Seal (Phoca Vitulina) Pups In Maine, John P. Skinner

Electronic Theses and Dissertations

Compared to other phocids seals, the maternal investment strategy of the small bodied female harbor seal (Phoca vitulina) is complex. Females are unable to fast for the entire duration of pup rearing and are therefore reliant on resources in the vicinity of the pupping aggregation to continue provisioning their pup by mid-lactation. At the same time, harbor seal pups are highly active during lactation which increases energetic costs to the female but also offers an opportunity for females to influence the behavioral development of her pup. To understand how females maximize their pup's survival it is important to …

Distribution And Diversity Of Bacterial Chemolithotrophs In Marine And Freshwater Sediments, Lisa M. Nigro

Electronic Theses and Dissertations

Bacterial chemolithotroph population structure has been investigated in Lowes Cove marine intertidal mudflat and Damariscotta Lake, Maine. A 492 to 495 fragment of the cbbL gene, coding for the large subunit of Form I ribulose-1,5- bisphosphate carboxylase/oxygenase (rubisco) was amplified from lake surface (upper 2 mm) sediments and mudflat surface (upper 2 mm), subsurface (5-7 cm), and Mya arenaria burrow wall sediments, as well as sulfide-oxidizing bacterial mat samples. Amplified DNA was used to construct cbbL clone libraries. Phylogenetic analysis showed that Damariscotta Lake cbbL clones were mainly of the 1C type, indicating a facultative carbon monoxide/hydrogen-oxidizing community. Conversely, clones …

State Of Maine Forester Licensure Program And Policy Review, Stephen F. Holt

Electronic Theses and Dissertations

Despite the continued importance of the forest resources to the State of Maine that led to the initial forester registration law in 1975, forester regulation has been the subject of only one program audit and policy review. That occurred 20 years ago, in 1986.

It is important to understand the need for a periodic forester regulatory program review even if there are no currently apparent or expected public interest or resource protection related issues.

There have been many significant changes since the last forester regulatory program and policy review that have impacted forest policy, management, and the related forestry based …

Structure-Function Analysis Of Nrage: A Protein Involved In Developmental Neural Apoptosis, Rebecca Cowling

Electronic Theses and Dissertations

The Neurotrophins and Bone Morphogenic Proteins (BMP) have both been implicated in the maintenance of cellular proliferation and apoptosis in the developing nervous system. Downstream of both signaling pathways is NRAGE, a member of the Melanoma Antigen (MAGE) gene family and, under BMP stimulation, activates p38 leading to caspase 3 cleavage. NRAGE possesses a highly conserved MAGE Homology Domain (MHD) and a second, less well conserved MHD (denoted MHD2) as well as a unique 25 tandem WQXPXX hexapeptide repeat region. Binding partners for the MHD and hexapeptide repeat regions have been identified but their cellular consequences have not been defined. …

Dynamics Of Forest Structure Under Different Silvicultural Regimes In The Acadian Forest, Michael R. Saunders

Electronic Theses and Dissertations

Research plots in many long-term studies of forest ecosystems often cannot be used for spatial modeling because of their small scale and nested inventory design. This has been unfortunate as these plots represent some of the best records of structural development as affected by forest management. I developed methodologies to reconstruct both tree height growth and spatial pattern in these types of plots from historical inventory records and stem-mapped data, and then retrospectively investigated 3-dimensional structural development as affected by five silvicultural and harvesting treatments (unmanaged natural area, commercial clearcut, fixed-diameter limit, 5-year selection, and 3-stage shelterwood— with and without …

The Effects Of Serotonin On The Courtship Behavior Of Drosophilia Melanogaster, Nicholas James Brandmeir

Electronic Theses and Dissertations

In Drosophila, the male courtship ritual is stereotyped and under the control of several genes including fruitless. In previous studies, it has been show that various fruitless alleles cause phenotypic abnormalities in the D. melanogaster courtship ritual. It is also known that there is a high level of co-expression of both the fruitless gene product and serotonin in specific neurons of the Drosophila CNS. This study examines the role of serotonin in the Drosophila male courtship ritual by using a mutant strain, Ddc^ts1,in which the production of serotonin is blocked above 30°C. In this study an increase in temperature caused …

Phenotypic Divergence Of Indigenous And Translocated Arctic Charr (Salvelinus Alpinus) Populations In Maine, Wendy K. Michaud

Electronic Theses and Dissertations

Selection on traits related to trophic ecology is recognized as an important contributing factor in adaptive divergence and speciation. For several freshwater fish species, including Arctic charr (Salvelinus alpinus), such selection is commonly reflected in relationships between diet, habitat use and phenotypic divergence. Trophic specializations that emerge have been extensively studied among sympatric forms, but much less is known of the extent of this type of divergence in allopatry. Trait differences among these forms are also thought to reflect thousands of years of evolution, making it difficult to examine root causes of such divergence in natural populations. Here, I address …

Vascular Morphometry Of The Retina In Antarctic Fishes Is Dependent Upon The Level Of Hemoglobin In Circulation, Jody M. Wujcik

Electronic Theses and Dissertations

Antarctic notothenioids express the circulating oxygen-binding protein hemoglobin (Hb) over a broad range of blood concentrations. White-blooded icefishes (Suborder: Notothenioidei, Family: Channichthyidae) are the only known adult vertebrates to lack Hb completely. In addition to its role in oxygen transport, Hb is the primary reactant in degradation of nitric oxide (NO). Thus, NO should be degraded at a slower rate in Hb-lacking icefishes than in Hb-expressing notothenioids, leading to higher steady-state levels of NO in the former group. Increased levels of NO should stimulate upregulation of angiogenesis, the growth and proliferation of new blood vessels from existing vasculature. Based upon …

Forest Disturbance History And Stand Dynamics Of The Coweeta Basin, Western North Carolina, Sarah Marie Butler

Electronic Theses and Dissertations

Understanding the patterns of past disturbance allows further insight into the composition, structure, and function of today’s forests. Disturbance history may also influence how forests will react to future stresses and disturbances. The disturbance histories of the mixed-oak forests at the Coweeta Hydrologic Laboratory (a 2,185 ha long-term research site with some history of harvesting) and the Joyce Kilmer Wilderness (a 6,805 ha old-growth forest with no known harvesting) located in southwestern North Carolina were studied using dendroecology. Dendroecology uses increment cores to determine tree ages and patterns of radial growth. In addition to evaluating the history of these two …

Relationship Between Balsam Woolly Adelgid Damage, Radial Growth, Climate And Stand Characteristics In Eastern Maine, Allison M. Kanoti

Electronic Theses and Dissertations

Balsam woolly adelgid (BWA) (Adelges piceae) is an insect pest of fir (Abies spp.) that was introduced to Maine in the early 1900’s. Within 50 years, it was found across the southern half of the state. BWA continued to kill balsam fir (Abies balsamea) in coastal sections of Maine but damage inland has been sporadic and scattered. Within the last decade increases in BWA damage severity and related fir mortality were reported in interior eastern Maine. This study investigated if the onset of BWA-related growth decline was a recent event; if climate trends coincided with growth reduction in BWA infested …

A Physiological Examination Of The Age-Related Decline In Photosynthesis In Picea Rubens, Stephanie L. Adams

Electronic Theses and Dissertations

Numerous conifer species undergo predictable age-related changes in productivity, photosynthesis and foliar morphology and anatomy. While these phenomena have been demonstrated for many species, the physiological mechanisms controlling them are not well understood. In order to better understand this issue, we examined four possible controls of the age-related decline in photosynthesis in red spruce: stomatal limitation, a decline in investment into photosynthetic capacity, nutrient limitations and a demand-side decline in sink: source relations. We investigated these age-related trends in physiology for juvenile, mid-age and old (mean age ~13, ~54 and ~128 years old) red spruce trees in a multi-cohort stand …

The Effect Of Mandatory Continuing Education On Practice Quality And Competency Of Professional Land Surveyors, Anthony Richard Vannozzi

Electronic Theses and Dissertations

Mandatory Continuing Education (MCE) has always been a "hot button" topic in the professions and land surveying is no exception. Though most other professions (i.e. medicine, education, accountancy, dentistry, nursing, etc.) have included scientifically based research as part of their debate on whether to make continuing education mandatory, no empirical studies in land surveying were found. Though the land surveying literature is replete with anecdotal discussions on the topic, (commentaries, editorials, policy statements, magazine articles, etc.), and tremendous energy is being expended within the land surveying profession in debating and making decisions regarding the MCE issue, the lack of hard …

Regeneration Strategies Of Japanese Barberry (Berberis Thunbergii Dc.) In Coastal Forests Of Maine, Jennifer D'Appollonio

Electronic Theses and Dissertations

Japanese barberry (Berberis thunbergii DC.) has become invasive in forests of the northeast since its U.S. introduction as an ornamental shrub in 1875. This non-native invasive species can occupy a wide range of environmental conditions, has a longer growing season than most native species, multiple methods of reproduction, and forms thickets under which few other plants can persist. Effective control strategies and management of invaded forest stands would be improved by knowledge of how Japanese barberry regenerates in the forest, whether it forms a seed bank, and to what extent it impacts other plant species. This study focused on the …

Tourism Stakeholders Envision A Sustainable Path: Strengthening Maine's No. 1 Industry Through The Blaine House Conference Recommendations, Elizabeth Munding

Electronic Theses and Dissertations

Tourism, as Maine’s No. 1 industry, draws approximately 44 million visitors annually who spend $6 billion and contribute $340 million in sales tax. Despite these figures, annual statistics show zero growth or, often, loss, with the exception of the outdoor recreation sector. The tourism industry, made of government bodies, recreation associations and individual businesses, depends on the health of the natural resources and the compliance of related players, such as landowners. Discontent exists with the state and the industry’s leadership. The quandary comes in determining which actions to take to improve the state’s existing nature-based tourism into a sustainable industry …

Wind Damage In Maine Forests: Trends And Vulnerability Assessment, Thomas Perry

Electronic Theses and Dissertations

The likelihood of windthrow or windsnap occurring in a forest stand includes numerous factors; however, past research suggests that these factors can be grouped into four broad categories: regional climate, topographic exposure, soil properties and stand characteristics (Mitchell, 1995). Of the three categories, stand characteristics are most commonly and easily modified through forest management. Vulnerability to wind damage in Maine may increase in the future because of three trends influencing stand conditions. One, Maine forests contain a considerable amount of balsam fir and red spruce, tree species that are considered particularly susceptible to wind damage. Two, extensive areas regenerated after …